The law, under Internal Revenue Code Section 401(a) states
REQUIREMENTS FOR QUALIFICATION. --A trust created or organized in the United States and forming part of a stock bonus, pension, or profit-sharing plan of an employer for the exclusive benefit of his employees or their beneficiaries shall constitute a qualified trust under this section --
(1), ... (2), ... (3), ...; and
401(a)(4) if the contributions or benefits provided under the plan do not discriminate in favor of highly compensated employees (within the meaning of section 414(q)). For purposes of this paragraph, there shall be excluded from consideration employees described in section 410(b)(3)(A) and (C ).
IRC 401(a)(4) is interpreted under the Treasury Regulations, one section of which is 1.401(a)(4)-5.
§1.401(a)(4)-5. Plan amendments and plan terminations
(a) Introduction
(1) Overview. --This paragraph (a) provides rules for determining whether the timing of a plan amendment or series of amendments has the effect of discriminating significantly in favor of HCEs or former HCEs. For purposes of this section, a plan amendment includes, for example, the establishment or termination of the plan, and any change in the benefits, rights, or features, benefit formulas, or allocation formulas under the plan. Paragraph (b) of this section sets forth additional requirements that must be satisfied in the case of a plan termination.
(2) Facts-and-circumstances determination. --Whether the timing of a plan amendment or series of plan amendments has the effect of discriminating significantly in favor of HCEs or former HCEs is determined at the time the plan amendment first becomes effective for purposes of section 401(a), based on all of the relevant facts and circumstances. These include, for example, the relative numbers of current and former HCEs and NHCEs affected by the plan amendment, the relative length of service of current and former HCEs and NHCEs, the length of time the plan or plan provision being amended has been in effect, and the turnover of employees prior to the plan amendment. In addition, the relevant facts and circumstances include the relative accrued benefits of current and former HCEs and NHCEs before and after the plan amendment and any additional benefits provided to current and former HCEs and NHCEs under other plans (including plans of other employers, if relevant). In the case of a plan amendment that provides additional benefits based on an employee's service prior to the amendment, the relevant facts and circumstances also include the benefits that employees and former employees who do not benefit under the amendment would have received had the plan, as amended, been in effect throughout the period on which the additional benefits are based.
(3) Safe harbor for certain grants of benefits for past periods. ...
(4) Examples. --The following examples illustrate the rules in this paragraph (a):
Example 1. Plan A is a defined benefit plan that covered both HCEs and NHCEs for most of its existence. The employer decides to wind up its business. In the process of ceasing operations, but at a time when the plan covers only HCEs, Plan A is amended to increase benefits and thereafter is terminated. The timing of this plan amendment has the effect of discriminating significantly in favor of HCEs.
Do you think the amendment has the effect of discriminating significantly in favor of HCEs or former HCEs? It's facts and circumstances, so the IRS has some leeway when they look at something like this. IMHO, I don't know if a foolproof correct answer is truly known until the IRS gets involved.
Looking at one side, just exactly how does this
discriminate significantly in favor of HCEs? Would that mean the forfeitures of the NHCEs may get allocated to HCEs? Doesn't that happen in lots of plans anyway? Maybe this could be discriminatory only if one of the HCE leaves before they achieve their 6th year of vesting service. If that happened, then it does appear to be discriminatory. But if neither HCE left before their 6th year, again, how would this specific amendment have the effect of significantly discriminating?
If they want to be mostly conservative, and if the HCEs only have a couple years of service now, perhaps the plan could be a little safer by adopting a 6-year graded vesting schedule that applies to all new employer contributions, that would impact the vesting of the HCEs too. Still not foolproof though.